Is there a consensus for metrics that track the qualitative condition of the ASI?
Science Citation Index would indicate if anybody has followed up on this 2013 study (too far behind at work and in life to track it down myself). A 2013-2023 update of the exchange between CAB-Beaufort and CAA would be interesting to see. I don't understand how the data charts in this paper connect to the conclusions stated in text. And the results for QEI and McClure Strait seem contradictory. I thought ice just moved south from the AO into the CAA but apparently there's more to it than that.
Howell, S. E. L., T. Wohlleben, M. Dabboor, C. Derksen, A. Komarov, and L. Pizzolato (2013), Recent changes in the exchange of sea ice between the Arctic Ocean and the Canadian Arctic Archipelago, J. Geophys. Res. Oceans,118, 3595–3607,doi:10.1002/jgrc.20265
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/jgrc.20265Excerpt from the Abstract:
"The presence of MYI in the CAA originating from the Arctic Ocean has been maintained by inflow at the QEI, which has increased since 2005. These recent increases in Arctic Ocean MYI inflow into the QEI can be attributed to increased open water area within the CAA that have provided more leeway for inflow to occur."
"Time series of Arctic Ocean-M'Clure Strait gate net total ice and multi-year ice area flux from (a) May to September and (b) October to November, 1997–2012. Positive and negative flux signs correspond to Arctic Ocean ice inflow and outflow, respectively."
"Time series of May to September net open water within the Western Parry Channel and May to September Arctic Ocean-M'Clure Strait net ice area flux, 1997–2012. Positive and negative flux signs correspond to Arctic Ocean ice inflow and outflow, respectively."
"Time series of Arctic Ocean-Queen Elizabeth Islands (North and South) gate net total ice and multi-year ice area flux from (a) May to September and (b) October to November 1997–2012. Positive and negative flux signs correspond to Arctic Ocean ice inflow and outflow, respectively."
"Time series of May to September net open water within the Queen Elizabeth Islands and May to September Arctic Ocean-Queen Elizabeth Islands (North and South) net ice area flux, 1997–2012. Positive and negative flux signs correspond to Arctic Ocean ice inflow and outflow, respectively."
Excerpts from Conclusions
"We utilized 16 years of RADARSAT imagery to estimate the sea ice area flux between the Arctic Ocean and the CAA at the M'Clure Strait and QEI (north and south) exchange gates for the months of May to November from 1997 to 2012. Over this period, the M'Clure Strait ice area flux was −1 × 10^3 km2 indicating net outflow to the Arctic Ocean but it is important to note that the interannual variability is high (i.e., ±21 × 10^3 km2). An examination of seasonal differences revealed that while Arctic Ocean ice inflow primarily occurred during the summer months (May to September) outflow dominates in the fall months (October to November). The QEI gates experienced a mean flux of +3 × 10^3 km2 from August to September with negligible ice exchange from May to July and October to November. These results indicate that Arctic Ocean ice inflow at the M'Clure Strait and QEI exchange gates during August and September play an important role in determining the annual sea ice minimum within the CAA.
Since 2007, Arctic Ocean ice inflow at the M'Clure Strait gate during the summer months has reduced considerably. We attribute the decrease to the increased frequency and location of high SLP anomalies over the Beaufort Sea and Canadian Basin that disconnect the Arctic Ocean polar pack ice from ice within the Western Parry Channel. While Arctic Ocean ice inflow has decreased at the M'Clure Strait in recent years, the QEI gates have experienced increases since 2005. The increase at the QEI gates can be attributed to increased open water within the QEI (and the channels to the south of the QEI) providing more leeway for atmospherically driven Arctic Ocean ice import to occur."
"Our analysis points out that despite reduced Arctic Ocean ice inflow into the CAA at the M'Clure Strait, ice inflow at the QEI has continued, thus maintaining the presence of Arctic Ocean MYI within the CAA. Although younger and thinner [Maslanik et al., 2011],
this MYI has continued to flow southward into the channels of the Northwest Passage."
"Sea ice conditions within the CAA during September have begun to decrease considerably in recent years, and the lack of Arctic Ocean ice inflow at M'Clure Strait has likely played a role."Legend for attached graph: "Comparison of 1997–2002 monthly May to November ice area flux at (a) the Arctic Ocean-M'Clure Strait and (b) the Arctic Ocean-Queen Elizabeth Islands (North and South) exchange gates between Kwok [2006] and this study. Positive and negative flux signs correspond to Arctic Ocean ice inflow and outflow, respectively.
To the extent that I understand this material, it seems that the May - November flux between the AO and Queen Elizabeth Islands could be useful as a monitor of ASI export dynamics, parallel to the Farm Strait monitoring. Especially if thinning ice along the southern border of the CAB and Beaufort, and ice loss in the CAA, is causing there to be increased export activity from the Arctic Ocean into the CAA.